MEDIUM: proxy: Store server_id_hdr_name as a struct ist

The server_id_hdr_name is already processed as an ist in various locations lets
also just store it as such.

see 0643b0e7e ("MINOR: proxy: Make `header_unique_id` a `struct ist`") for a
very similar past commit.

include/haproxy/proxy-t.h

@@ -354,8 +354,7 @@ struct proxy {
 	struct net_addr except_xot_net;         /* don't x-original-to for this address. */
 	struct ist fwdfor_hdr_name;			/* header to use - default: "x-forwarded-for" */
 	struct ist orgto_hdr_name;			/* header to use - default: "x-original-to" */
-	char *server_id_hdr_name;                   /* the header to use to send the server id (name) */
+	struct ist server_id_hdr_name;                   /* the header to use to send the server id (name) */
-	int server_id_hdr_len;                      /* the length of the id (name) header... name */
 	int conn_retries;			/* maximum number of connect retries */
 	unsigned int retry_type;                /* Type of retry allowed */
 	int redispatch_after;			/* number of retries before redispatch */

src/cfgparse-listen.c

@@ -1383,12 +1383,11 @@ int cfg_parse_listen(const char *file, int linenum, char **args, int kwm)
 		}
 
 		/* set the desired header name, in lower case */
-		free(curproxy->server_id_hdr_name);
+		istfree(&curproxy->server_id_hdr_name);
-		curproxy->server_id_hdr_name = strdup(args[1]);
+		curproxy->server_id_hdr_name = istdup(ist(args[1]));
-		if (!curproxy->server_id_hdr_name)
+		if (!isttest(curproxy->server_id_hdr_name))
 			goto alloc_error;
-		curproxy->server_id_hdr_len  = strlen(curproxy->server_id_hdr_name);
+		ist2bin_lc(istptr(curproxy->server_id_hdr_name), curproxy->server_id_hdr_name);
-		ist2bin_lc(curproxy->server_id_hdr_name, ist2(curproxy->server_id_hdr_name, curproxy->server_id_hdr_len));
 	}
 	else if (strcmp(args[0], "block") == 0) {
 		ha_alert("parsing [%s:%d] : The '%s' directive is not supported anymore since HAProxy 2.1. Use 'http-request deny' which uses the exact same syntax.\n", file, linenum, args[0]);

src/mux_fcgi.c

@@ -2043,8 +2043,7 @@ static size_t fcgi_strm_send_params(struct fcgi_conn *fconn, struct fcgi_strm *f
 					}
 
 					/* Skip header if same name is used to add the server name */
-					if (fconn->proxy->server_id_hdr_name &&
+					if (isttest(fconn->proxy->server_id_hdr_name) && isteq(p.n, fconn->proxy->server_id_hdr_name))
-					    isteq(p.n, ist2(fconn->proxy->server_id_hdr_name, fconn->proxy->server_id_hdr_len)))
 						break;
 
 					memcpy(trash.area, "http_", 5);
@@ -2062,15 +2061,15 @@ static size_t fcgi_strm_send_params(struct fcgi_conn *fconn, struct fcgi_strm *f
 				break;
 
 			case HTX_BLK_EOH:
-				if (fconn->proxy->server_id_hdr_name) {
+				if (isttest(fconn->proxy->server_id_hdr_name)) {
 					struct server *srv = objt_server(fconn->conn->target);
 
 					if (!srv)
 						goto done;
 
-					memcpy(trash.area, "http_", 5);
+					p.n = ist2(trash.area, 0);
-					memcpy(trash.area+5, fconn->proxy->server_id_hdr_name, fconn->proxy->server_id_hdr_len);
+					istcat(&p.n, ist("http_"), trash.size);
-					p.n = ist2(trash.area, fconn->proxy->server_id_hdr_len+5);
+					istcat(&p.n, fconn->proxy->server_id_hdr_name, trash.size);
 					p.v = ist(srv->id);
 
 					if (!fcgi_encode_param(&outbuf, &p)) {

src/mux_h1.c

@@ -2143,8 +2143,8 @@ static size_t h1_process_mux(struct h1c *h1c, struct buffer *buf, size_t count)
 				}
 
 				/* Skip header if same name is used to add the server name */
-				if (!(h1m->flags & H1_MF_RESP) && h1c->px->server_id_hdr_name &&
+				if (!(h1m->flags & H1_MF_RESP) && isttest(h1c->px->server_id_hdr_name) &&
-				    isteqi(n, ist2(h1c->px->server_id_hdr_name, h1c->px->server_id_hdr_len)))
+				    isteqi(n, h1c->px->server_id_hdr_name))
 					goto skip_hdr;
 
 				/* Try to adjust the case of the header name */
@@ -2213,11 +2213,11 @@ static size_t h1_process_mux(struct h1c *h1c, struct buffer *buf, size_t count)
 
 				/* Now add the server name to a header (if requested) */
 				if (!(h1s->flags & H1S_F_HAVE_SRV_NAME) &&
-				    !(h1m->flags & H1_MF_RESP) && h1c->px->server_id_hdr_name) {
+				    !(h1m->flags & H1_MF_RESP) && isttest(h1c->px->server_id_hdr_name)) {
 					struct server *srv = objt_server(h1c->conn->target);
 
 					if (srv) {
-						n = ist2(h1c->px->server_id_hdr_name, h1c->px->server_id_hdr_len);
+						n = h1c->px->server_id_hdr_name;
 						v = ist(srv->id);
 
 						/* Try to adjust the case of the header name */

src/mux_h2.c

@@ -5349,8 +5349,8 @@ static size_t h2s_bck_make_req_headers(struct h2s *h2s, struct htx *htx)
 			list[hdr].v = htx_get_blk_value(htx, blk);
 
 			/* Skip header if same name is used to add the server name */
-			if ((h2c->flags & H2_CF_IS_BACK) && h2c->proxy->server_id_hdr_name &&
+			if ((h2c->flags & H2_CF_IS_BACK) && isttest(h2c->proxy->server_id_hdr_name) &&
-			    isteq(list[hdr].n, ist2(h2c->proxy->server_id_hdr_name, h2c->proxy->server_id_hdr_len)))
+			    isteq(list[hdr].n, h2c->proxy->server_id_hdr_name))
 				continue;
 
 			/* Convert connection: upgrade to Extended connect from rfc 8441 */
@@ -5416,11 +5416,11 @@ static size_t h2s_bck_make_req_headers(struct h2s *h2s, struct htx *htx)
 	BUG_ON(!sl);
 
 	/* Now add the server name to a header (if requested) */
-	if ((h2c->flags & H2_CF_IS_BACK) && h2c->proxy->server_id_hdr_name) {
+	if ((h2c->flags & H2_CF_IS_BACK) && isttest(h2c->proxy->server_id_hdr_name)) {
 		struct server *srv = objt_server(h2c->conn->target);
 
 		if (srv) {
-			list[hdr].n = ist2(h2c->proxy->server_id_hdr_name, h2c->proxy->server_id_hdr_len);
+			list[hdr].n = h2c->proxy->server_id_hdr_name;
 			list[hdr].v = ist(srv->id);
 			hdr++;
 		}

src/proxy.c

@@ -1441,7 +1441,7 @@ void proxy_free_defaults(struct proxy *defproxy)
 	ha_free(&defproxy->conn_src.iface_name);
 	istfree(&defproxy->fwdfor_hdr_name);
 	istfree(&defproxy->orgto_hdr_name);
-	ha_free(&defproxy->server_id_hdr_name); defproxy->server_id_hdr_len = 0;
+	istfree(&defproxy->server_id_hdr_name);
 
 	list_for_each_entry_safe(acl, aclb, &defproxy->acl, list) {
 		LIST_DELETE(&acl->list);
@@ -1607,10 +1607,8 @@ static int proxy_defproxy_cpy(struct proxy *curproxy, const struct proxy *defpro
 	if (isttest(defproxy->orgto_hdr_name))
 		curproxy->orgto_hdr_name = istdup(defproxy->orgto_hdr_name);
 
-	if (defproxy->server_id_hdr_len) {
+	if (isttest(defproxy->server_id_hdr_name))
-		curproxy->server_id_hdr_len  = defproxy->server_id_hdr_len;
+		curproxy->server_id_hdr_name = istdup(defproxy->server_id_hdr_name);
-		curproxy->server_id_hdr_name = strdup(defproxy->server_id_hdr_name);
-	}
 
 	/* initialize error relocations */
 	if (!proxy_dup_default_conf_errors(curproxy, defproxy, &tmpmsg)) {